I actually made an account just to comment on this specific manga because I've been enjoying it a lot. It may be because of some personal experiences I had, but here's an anecdote for you...
When I was in high school, I played on the girls tennis team and used to be the manager of the boys tennis team. There was this one upperclassman who I didn't really like and found him to be overly hyper/annoying in my Spanish class. He was also on the tennis team and once forgot my name, calling me "Naomi" instead. Then he got all the other boys to call me that (many of them seriously thought it was my real name) and it annoyed the hell out of me. We also had assigned seats in Spanish class and had to sit next to each other for a good portion of the year.
Lemonade really reminds me a lot of him. I really, really didn't like him at the time, but when I look back, he was very nice, eager, and attractive young man. I never noticed it, but he always supported his teammates and took tennis very seriously. I feel bad now that I didn't recognize his positive qualities, but at least our little feud turned into a friendly rivalry by the time he graduate. A friend once said that boys pick on girls that they like and maybe that was what was happening (it wasn't, trust me). My petty fighting with him is actually one of my fond high school memories.
Because we see Keita through Youko's eyes, we don't really get to see why people like him so much (his charisma, energy, etc.). And I think Youko does a great job of characterizing adolescent insecurities as well as struggling with one's sexuality. Even though the pace is slow for some, I'm enjoying how it quietly showcases Youko's understanding of the world around her and of herself. Sure, there will eventually be yuri, but I love this manga because it's really a coming of age story that feels close to home for me.
As for this latest chapter, Keita was trying to say that he's no longer calling her Imoko because she's his old love's little sister. Instead, he calls her Imoko because that's his cherished nickname for her. It was like how that boy I knew called me Naomi to piss me off at first, but then it just became who he knew me as.
This is a very long comment, but I felt like offering a different perspective on Lemonade, aside from the for explicit yuri. I look forward to every chapter and I'm grateful to the people who work hard to put this up here for all of us to read.
But, did your entire high school life revolve about what that guy liked and disliked? About what he called you? about who was it that he loved? Did your entire personality revolve around your friendliness or animosity towards this guy? because this is pretty much what happens with Lemonade. Even when Youko is having a revelation about her feeling towards Maki, we still have this guy's shadow floating around. We just can't get a break from this guy, and is making everyone irritated. He has way too much presence in the entire story.